The present invention relates to devices for delivering, administering, dispensing, injecting and infusing substances, and to methods of making and using such devices. More particularly, it relates a container for storing a product to be injected, especially a therapeutic or diagnostic liquid, and to an injection device comprising, incorporating and/or capable of using such a container.
The present invention relates to containers of the type comprising a container body and a piston body, which is arranged in the container body in a sliding manner and which, to dispense the product, can be displaced between a rear end position that determines a maximum filling of the container and a front end position. Containers of this type are used in medical injection devices for storing a therapeutic or diagnostic liquid that is to be injected. By the piston body being advanced toward a dispensing opening of the container, the liquid is dispensed into a hollow needle. The dispensing can be dosed by controlled displacement of the piston body.
Containers of the aforementioned type are always designed with a round, slender basic shape. A small base area of the piston body has the disadvantage that comparatively high pressures have to be applied to advance the piston body for dispensing the liquid. In containers of the aforementioned type, the liquid to be injected is dosed with the aid of a dosing mechanism that acts directly on the piston body, so that the dose to be injected is made available in the container body itself. This requires a comparatively elaborate dosing and displacement mechanism for preparing the dose and effecting a controlled advance of the piston body.
Injection devices for self-medication by the patient require comparatively small external dimensions of the injection device to ensure optimal transportability. Also desirable is a dosing and displacement mechanism for dosed dispensing of the liquid, which has a comparatively low energy requirement.
DE 196 52 708 A1 discloses a plastic syringe body for medical purposes of the aforementioned type, with a round and slender basic shape. An opening ratio, defined by the ratio of a maximum height of the container body to a maximum distance between side walls of the container body, is considerably greater than one. To be able to apply the comparatively high pressure required for advancing the piston body with minimal force, the base area of the piston is comparatively small, which limits the capacity of the container body and necessitates a large overall height of an injection device receiving the container body.
WO 00/02605 discloses a medical injection device for administration of insulin, with a container of the aforementioned type. A sufficient capacity of the container body necessitates a comparatively large overall height of the injection device, which is disadvantageous especially for self-treatment by patients using portable injection devices.